Hydraulic transmission and clutch



2 Sheets-Sheet l May 13 1947 A. L.. DoNAHEw ErAL.

I HYDRAULIC TRANSMISSION AND CLUTCH Filed Sept. 2]., 1943 May 13, 1947.

A. L. DoNAHEw ETAL 2,420,305 HYDRAULIC TRANSMISSION ANDy CLUTCH FiledSept. 2l, 1945 2 Sheets- Sheet 2 Patented May 13, 1947 HYDRAULICTRANSMISSION lCLUTCH Arthur L. Donahevv,vv United States Army,4 andWilliam H. De La Vergne, Washington, D. C.

ApplicationSeptember 21, 1943, Serial No.75`03,310 l 4 Claims. (Cl.192-61) (Granted under' the act of March 3, 1883,@ amended April v30,`1928; 370 0. G. 757,)

The invention described herein may be manun factured and used by or forthe Goverment forv governmental purposes, without payment of `anyroyalty thereon.

This invention relates to a hydraulic power 'transmission and clutchapplicable to practically any type of equipment in whicha variable speeddrive is required such as automotive vehicles.

One of the objects ofthe invention is to provide avariable hydraulictransmission and clutch wherein power is transmitted from 'a drivingmember of a power unit t'o a driven member through the medium of Va gearmechanismncluding means adapted to generate pressures on a iiuid tosubstantially any amount for increasing the power transmitted from thedriving member to the drive-n member, and means for controllingthepressures generated by the first-mentioned means on the fluid inaccordance with the varying conditions of load and speed. V

around the sun gear but do not transmit any ro tary motion thereto,ythuscausing the driven memberto remainstationary. Should the valves beoperated to completely close the outlet pas-f sages, the transmissionfluid is trapped inthe gear housing and the planet gearsgenerate such' apressure on the fluid that they are brought to a standstill and lockedin mesh'with thelsun gear,

thereby providing a direct coupling betweenthe driving member and drivenmemberz If the valves are operated intermediate their completelv closedor opened positions; the sungear is'driven to al certain extent by theVplanet gears with slippage relative to the planet gears. In case thevalves are completely closed and the planet gears have genera-ted morepressureon the transmis- Another object of the invention is to provide avariable fluid transmission and clutch in lwhich power is transmittedfrom a driving shaft' of a power unit to a driven shaft at variablespeed ratios through a pump adapted to generatevariable pressures on afluid medium 'and in which the variable generated pressures may bemanually controlled whereby an operator of the power unit is enabled torapidly control the application of power from the driving shaft to thedriven shaft and to secure transmission conditionsv of a-iree powerunit, positive hydraulic speed reduction, direct coupling drive andpermits slippage within the entire rage of the rotative speedsregardless of the speeds of the power unit. Briefly stated, the instantinvention is applicable to any prime mover wherein power is required tobe transmitted at variable speeds from a driving member to a drivenmember and isdirected to a driving rotor in the form of a gear housingcontaining a hydraulic gear pump of.

the epicyclic type in whichvrotary motion of the prime mover istransmitted from a plurality of 4planet gears mounted on the gearhousing to a sion fluid than is necessary to carry a predetermined load,`the valves are acted upon by the exe' cess fluid pressure against theaction of asprin'g to release the pressure of the iiuid on the valves,therebyA preventing any harmful excessv load being applied to the primemover. i

-The `improved hydraulic transmission is particularly adapted to beemployed in vehicles such as motor cars and the like, in which aninternal combustion engine is 'used as a source of motive power and bythe employment of the instant invention the conventional gearand clutchmech-v anism-and. also the means for manually control- ,ling the gearand clutch mechanism generally type havebeen employed in aneiortl toproduce control of thek gear pump dischargepressures of the transmissioniiuid, but the instanttransmisvsion differs particularly rfro'mknown,devicesy of this type inthat the control of the discharge of thetransmission-fluid is vaccomplished by.- the manipulation of a pluralityof valves located on the transmission andA upon the valves being openedthe transmission iiuid is discharged from the r`unit to van externalreservoin withthe fluid discharge taking place Ythrough radiallyextending outlet passages, witlifoverload protection being accomplishedby applying generated fluid pressures to the front end oethevalvesagainst the action of a spring, whereby a positive and simple method ofoverload protection is provided.

With the above and other objects and advantages in view, the inventionconsists of cer 2 42o 30's a tain features of construction and operationof parts which will hereinafter be described and shown in theaccompanying drawings, in which:

Fig. 1 is a fragmentary vertical axial sectional view through thehydraulic transmission and clutch taken on line |-I of Fig. 2, showingFig. 2 is a cross-sectional view thereof taken on',

line 2-2 of Fig. l;

Fig. 3 is a fragmentary transverse cross-sectional view taken on theline 3-3 of Fig. 2;

Fig. 4 is a fragmentary detailmview of a portion of a gear housing; .I i

Fig. 5 is a fragmentary vertical axial sectional viewpartly in elevationof the hydraulic transmission-and clutch showing the valves in an openposition.`

Fig. 6 is a detail plan view of one side of an annular channel memberhaving a fragmentary portion of a fluid intake conduit mounted thereonused in carrying out the invention; and

Fig. '7 is a detail side elevation of a plate used on the gear housing.--Referring more specifically to the drawings, the improvedr hydraulictransmission and clutch indicated generally by A is rotatably mountedwithin an outer casing or reservoir I closed at one end by a. wall 2 andcomprises a gear housing 3 connected to a prime mover (not shown)through a driving shaft '4, which in the case of the usual automobilewould be the crankshaft of the engine.

, The gear housing 3 is formed of a central body 5 and side plates 6 and1 joined together by bolts 3. The side plate 6 is provided with a hub 9formed integral with and extending outwardly therefrom, said hub 9 beingixedly connected' to the inner end of the driving shaft 4 by bolts I0.The side plate 1 is provided with a sleeve I and a hollow hub I2 whichextend outwardly therefrom in an opposite direction from the hub 9 onthe side plate 6. The sleeve I is rotatably mounted at its Aouter end ina bearing I3 and surrounds a driven shaft I4 which is in alinement withthe driving shaft 4. The driven shaft I4 is rotatably mountedrat itsinner end in bearings I5 and I3,

with the bearing I5 being carried by a boss I1 formed on the innersurface of the side plate 6 and the bearing I6 being fitted into thehollow hub I2 of the side plate 1. 'I'he outer end of the driven shaftI4 is mounted in a bearing I B carried by a collar 9 mounted on thecasing I.

The central body 5 of the gear housing 3 has a main chamber 20formedcentrally therein which fits snugly around a sungear 2| xedly mountednel 39 having a, washer 3| mounted therein, which washer 3| is providedwith apertures 32 registering with the intake ports 23, Fig. 3. Anannular channel member 33 is non-rotatably supported on the hub 9 bymeans of studs 34 mounted on the end wall 2 of casing I, with theannular open end 33' of the .channel member 33 extending into thechannel 30 and abutting against the outer edges of the washer 3|. Thestuds 34 extend through ears 3l. suitably spaced aroimd the channelmember 33 and have expansion springs 36 mounted on the inner end of thedriven shaft I4 by splines 22 and auxiliary chambers 23 are formed -inthe,

body 5, said auxiliary chambers 23 communicating with the main chamber20 as illustrated in Fig. 2 and having planet gears 24 snugly fittedtherein. The planet gears 24 mesh with the sun gear 2| and are xedlymounted on shafts 25 rotatably mounted in bearings 25 carried by theside plates 6 and 1. The body is also provided with channels 21 and theside plate 3 is provided with intake ports 23, with one of each of thechannels 21 communicating with one of each of the auxiliary chambers 23and with one of each` of the intake ports 23. The intake ports 28 extendthrough the side plate 6 and are surrounded by a circular flange 29formed on the outer surface of the side plate 5. Y

The ange 29 andthe outer periphery of the hub 9 of the side plate 6 forman annular chantoward the periphery of the gear housing 3 and theninwardly at their other ends 4I through the inner surface of the sideplate 6. Exhaust or` outlet passages 42 are formed in the central body 5of the gear housing 3, with one of each of the exhaust passages 42extending outwardly in a curved manner through the periphery of the gearhousing body 5 from one of each of the auxiliary chambers 23 and fromthe main chamber 20, with the outer ends of the exhaust passages 42being equally spaced around the driving rotor 3.

The inner ends 43 of the by-passes 39 are connected in communicationwith the exhaust passages 42 through apertures 43 formed in the body 5of the driving rotor and the ends 4| of the bypasses 39 are connected incommunication with the exhaust passages 42 through transverselyextending valve openings 44 also formed in the gear housing body 5. Thevalve openings 44 have valves'45 movably mounted therein, which valves45 are made in the form of plugs or pistons extending through holes 43equally spaced from the the valves 45 are reduced in diameter formingplug portions 41 adapted to engage within the ends 4| of the by-passes39 and the outer ends of the valves 45 are connected by pins 43 to theouter ends of arms 49 extending outwardly from acollar 50 slidablymounted on and rotatable with the sleeve I| by means of splines 5|. 'Ihecollar 50 is engaged by one end of an expansion spring 52, with theother end of the spring 52 engaging a washer 53 abutting against theinner surface of the casing I whereby the collar 50 is normally held bythe spring 52 for holding the valves 45 in a closed position asillustrated in Fig. 1. A clamping ring 55 made of semi-circular sectionshaving pins 59 thereon is mounted in an annular groove 51 formed in thecollar 50. I'he pins 55 on the semi-circular sections of the ring 55 areengaged by the forked ends 53 of a yoke 59 mounted on a rock shaft GIIwhich may beactuated by any suitable means such as a lever 3|.

In operation, assuming that a suitable fluid such as oil has beenprovided in the casing or reservoir I, theiluid will enter the annularchannel member 33 through intake conduit 31 and pass into the gearhousing 3 through the intake ports 28 inside plate 6. With the drivingshaft 4 and housing 3 rotated in the direction as indicated by thearrows, the planet gears V24 rotating in mesh around the sun gear 2|Will pump the fluid into the exhaust passages 42 and, should 36 abut atone of their .dicatecL the valves 45 be actuated to an open position asillustrated in Fig. 5, the fluid will pass4 through the exhaust.passages 42 andy be returnedtothe casing I whereby the planet gears 24will. be rotated around the sun gear 2| without producing-any torquethereon in driving the driven shaft I4. The valves 45 are actuated to anopen position by actuating the lever 6I which inturn.,v

rotates the rock shaft 60, thus moving the yoke sages 42, the planetgears 24 vwill produce a ceri tain pressure on the operating fluid dueto the restricted flow of the operating fluid through the "i, exhaustpassa ges 42 whereby the planet gears are '.caused to rotate at areduced speedaround the Vsunl gear. This reduced speed causes the planetgears 24 to impart a certain torque to thesun gear 2| for driving thedriven shaft I4, but atthe' same time permitting slippage of the planetgears. Should the valves 45 be actuated to completely close the exhaustpassages 42, Withthe plug portions 4l on the inner ends of the valvesengaging in the ends 4I of the by-passes 39, .the planet gears 24 willbe operated until they cannot generate any more pressure on theoperating fluid whereby they will be brought to a stop and locked inmesh with the sun gear 2|, thus providing a direct drive from thedriving shaft 4 to the driven shaft I4. In case the pressure of theoperating fluid becomes excessive, the pressure of the fluid in theby-passes 39 acts against the plug portions 41 of the valves 45- with asufcient pressure to force the valves outwardly from engagement fwiththe ends 4I of the by-passes 39'whereby the operating fluid may pass`through the bypasses 39 and the exhaust passages 42 to release thepressure of the operating fluid. The rotary gear pump of the epicyclictype used to transmit torque from the driving shaft to the driven shaftcontains the inherent characteristics yoi driving the driven shaftthrough an oil cushion, thus preventing transmittal of any destructiveforces and performs transmittal of rotation and power without mechanicalfriction.

It will thus be seen that there is provided an efficient form ofhydraulic transmission and,l

clutch which is well adapted for the purpose in- Even though there hasbeen herein shown and described certain features of construction andoperation of parts, it is nevertheless to be understood that variouschanges may be made therein, if the changes do not depart from thespirit or scope of the claims.

Having thus described our invention, what we claim as new and wish tosecure by Letters Patent is:

l. A hydraulic transmission and clutch comprising a casing adapted' tocontain a. fluid, a driving member and a driven member in axialalinement mounted on said casing, a gear housing ilxedly mounted on saiddriving member and having intake ports and outlet passages formedtherein, said intake ports adapted to admit fluid from the casing intosaid housing, by-passes formed in said housing and communicating withsaid outletv passages, an epicyclic gear pump r0- tatably connectingsaidhousing to said'driven 6 member, said pump comprising a sun gearxedly mounted 0n said driven member and planet gears rotatably mountedin spaced relation on said housing, said planet gears meshing with saidsun gear and adapted to pump iluidunder pressure from said housingthrough said outlet passages, a manually operated valve control meansincludilfl..a spring and having valves including plug ends connectedthereto, said valves rextending into said housing Vand intercepting saidoutlet passages for controlling the opening and closing thereof andsaidby-passes upon the actuation of said control means, said control meansadapted to actuate said valves to a complete opening, closing orintermediate position for controlling the amount of pressure generatedon the fluid, whereby the planet gears may rotate freely on said sungear for permitting the driven member to be idle or to effect rotationof the sun gear for driving the driven member at a speed in accordancewith load conditions, said plug ends of said valves adapted to engagesaid by-passes upon the Valves being actuatedto a completely closedposition and to be acted upon by the fluid pressure through saidby-passes to actuate said valves against the action of said springfor'releasing the fluid pressure upon the planet gears generating apressure 'above a predetermined amount.

2. A hydraulic transmission and clutch, comprising a casing adapted tocontain a fluid,ja driving member and a. driven member in axialalignment mounted on said casing, -a gear housing ilxedly mounted onsaid driving member and having intake ports and discharge passagesformed therein, said intake ports adapted to admit fluid from saidcasing into said housing, a sleevel provided. on said housing androtatably mounted on said driven member, ley-passes lformed in saidhousing and communicating with said discharge passages, anv epicyclicgear pump rotatably connectingsaid housing to said driven member, saidpump comprising a sun gear ilxedly mounted on said driven member, andplanet gears rotatably mounted on said housing, said planet gearsmeshing with said sun gear and adapted to pump fluid under pressure fromthe gear housing through said discharge passages,

manually operated valve control means including a collar slidablymounted on and adapted to rotate with said sleeve, valves includingAplug ends connected to said collar, said valves extending into saidhousing and intercepting said discharge passages for controlling theopening and closing thereof and said valve control means adapted toactuate said valves to a complete opening, closing or intermediateposition for, controlling the amount of pressure generated on the fluid,whereby the planet gears may rotate freely on said sun gear forpermitting the driven member to be idle or to eilect rotation of the sungear for driving the driven member at a speed in accordance with loadconditions, said plug ends of said valves engaging said by-passes uponthe Valves being actuated to completely closed position and to be actedupon by the fluid pressure through said bypasses to actuate said valvesfor releasing the fluid pressure upon the planet gears generating apressure above a predetermined amount.

3. A hydraulic transmission and clutch comprising a casing adapted tocontain a fluid, a driving member and a driven member Vin axialalignment mounted on said casing,.a gear housing flxedly mounted on saiddriving member, said gear housing having intake ports formed therein andincluding a. central body having channels,

outlet passages, a main chamber and` auxiliary chambers formed therein,said auxiliary chambers communicating with said main chamber, one ofeach of said channels communicating with `one of each of said auxiliarychambers and with one of each of said intake ports, an epicyclic gearpump rotatably connecting said housing to` said driven member, saidpumpcomprising a sun gearV including a spring and having valves provided lwith plug ends connected thereto, said valves extending into saidhousing vand intercepting said outlet passages for controllingtheopening and closing thereof and said valve control means adapted toactuate said valves to` a complete opening, closing or intermediateposition for controlling the amount o! pressure' generated lon thefluid, whereby the planet gears may rotate freely on said sun gear forpermitting the driven mem-` ber to be idle or to eilectrotation of thesun gear for driving the driven member ata speed in accordance with loadconditionsfsaid plug ends of said valves adapted to engage saidby-passes upon the valves being actuated to completely closed positionand -to be acted upon by the fluid pressure through said by-passes toactuate'said valves against the action of said springs for releasing theiiuid' pressure upon. the planet gears generating a pressure above apredetermined amount. l l J 4. A hydraulic transmissionand clutchcomprising a casing adapted to contain a fluid, a driving member and adriven member in axial alignmenty mounted on said casing, a gear housinglxedly mounted on said driving member, said gear housing including acentral body and side plates, one of said side plates containing intakeports and having a huh mounted on said drivingY member and another of'said sideplates having a sleeve rotatably mounted on said drivenmember,

driven member and Y planet gearsV rotatably mounted in spaced relationon,said centralibody, said planet gears meshing with said sun gear andadapted to pump iluid under pressure from said` housingthrough saidoutlet passages, a manually operated valve control means having valvesincluding plug ends connected thereto, said `valves y extending intosaid housing and intercepting'said l, f outlet passages forconi-.rolling the opening; and closing thereof upon the actuation ofsaid control means, said control means adapted to actuate said valves toa complete opening, closing or in termediate position for controllingthe amount of pressure generatedon the iluid, wherebythe planet gearsmayrotate treelyon saidfsun gear. for permitting the driven member-t0 beVidle or; to effectrotation of the sun gear fordriving the: drivenymember at a 4speed in accordance with load conditions, said plug ends ofsaidivalves en,-

gaging said by-passes upon the valvesbeing actuated to completely`closed position and to be acted Y upon by the duid pressure through saidby-passes to actuate said valves for releasing the fluid pressure uponthe planet gears generating a pressure above a predetermined amount. i

r ARTHUR L. p

WILLIAM H. DE LA VERGNE.

REFERENCES CITED The following references are of record in the ille ofthis patent:

` UNITED STATES PATENTS Number Name Date y "881,472 Hollister Mar. 10,1908 2,311,237 ,Loveday n Feb. 16, i943 1,450,679 Grafenstah Apr. 3,1923 1,561,549 vKraftv 1 Nov. '17, 1925. 2,066,450 Bascle Jan. 5, 1937FOREIGN PATENTS Number Country, Date 407,939 i ,Great Britain Mar. 26,1934 408,584 Great Britainp Apr. 10,1934

417,017 Great,Britain'-..' Sept. 26, 1934 l386,870 Great Britain Jan.26, 1933

